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MSC.1/Circ.1598 24 January 2019
GUIDELINES ON FATIGUE
1 The Maritime Safety Committee, at its seventy-first session
(19 to 28 May 1999), considered the issue of human fatigue and
agreed to develop practical guidance to provide appropriate
information on fatigue to all parties concerned. 2 Consequently, at
its seventy-fourth session (30 May to 8 June 2001), the Committee
approved MSC/Circ.1014 on Guidance on fatigue mitigation and
management. 3 The Committee, at its ninety-fourth session (17 to 21
November 2014), agreed to undertake a revision of the Guidance on
fatigue mitigation and management and instructed the Sub-Committee
on Human Element, Training and Watchkeeping (HTW) to conduct the
review. 4 Accordingly, the Committee, at its 100th session (3 to 7
December 2018), approved the annexed Guidelines on fatigue,
finalized by the HTW Sub-Committee, at its fifth session (16 to 20
July 2018). 5 Member States are invited to:
.1 bring the Guidelines to the attention of their maritime
Administrations and all stakeholders, including seafarers,
companies, naval architects/ship designers and training
providers;
.2 use the Guidelines as a basis for disseminating information
on fatigue (for
example by means of pamphlets, video training modules, seminars
and workshops); and
.3 take the Guidelines into consideration when determining
minimum safe
manning.
6 Companies are strongly urged to take the issue of fatigue into
account when developing, implementing and improving safety
management systems under the ISM Code. 7 This circular supersedes
MSC.1/Circ.1014 on Guidance on fatigue mitigation and management,
approved on 12 June 2001.
* * *
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ANNEX
GUIDELINES ON FATIGUE
INTRODUCTION
1 For the purpose of the Guidelines, the following definition
for fatigue is used:
"A state of physical and/or mental impairment resulting from
factors such as inadequate sleep, extended wakefulness, work/rest
requirements out of sync with circadian rhythms and physical,
mental or emotional exertion that can impair alertness and the
ability to safely operate a ship or perform safety-related
duties."
2 Fatigue is a hazard because it may affect a seafarer's ability
to do their job effectively and safely. Importantly, fatigue
affects everyone regardless of skill, knowledge and training. The
effects of fatigue can be particularly dangerous in the
transportation sector, including the shipping industry. All
stakeholders should be alert to the factors which may contribute to
fatigue, and make efforts to mitigate and manage the risks posed by
fatigue. 3 Effectively dealing with fatigue in the maritime
environment requires a comprehensive and holistic approach that
recognizes ship design, and the roles and responsibilities of all
stakeholders in the mitigation and management of fatigue. An
effective fatigue management strategy begins with determining
operational workload requirements and matching onboard manning
levels and onshore support resources, combined with efficient
management of workload and hours of work and rest on board the
ship. There is no one-system approach to addressing fatigue, but
there are certain principles that should be addressed in order to
gain the knowledge and the understanding to manage this human
element issue. Objective 4 The Organization has developed these
Guidelines to assist all stakeholders in better understanding their
roles and responsibilities in mitigating and managing the risk of
fatigue. 5 The Guidelines provide information on the causes and
consequences of fatigue, and the risks it poses to the safety and
health of seafarers, operational safety, security and protection of
the marine environment. It has been prepared to assist all
stakeholders in contributing to the mitigation and management of
fatigue. Organization 6 The Guidelines are composed of modules each
devoted to an interested party. The modules are as follows:
.1 Module 1 Fatigue
.2 Module 2 Fatigue and the company
.3 Module 3 Fatigue and the seafarer
.4 Module 4 Fatigue, awareness and training
.5 Module 5 Fatigue and ship design
.6 Module 6 Fatigue, the Administration and port State
Authorities
.7 Appendix 1 Examples of sleep and fatigue monitoring tools
.8 Appendix 2 Example of a fatigue event report information
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How to use these modules 7 The modules are all interrelated; it
is recommended that all parties become familiar with module 1,
which contains general information on fatigue. It may be beneficial
if the reader (interested party) becomes familiar with modules
other than the immediately applicable one. 8 These guidelines
should be taken into consideration when:
.1 developing, implementing and maintaining safety management
systems under the ISM Code;
.2 promoting fatigue mitigation and management; .3 promoting
awareness of the causes and consequences of fatigue and
developing and delivering training programmes and courses; .4
conducting casualty or accident/incident investigations; and .5
preparing applications for minimum safe manning documents or
when
determining minimum safe manning levels for ships. Future work 9
These Guidelines are a living document; they should be updated
periodically as research reveals new information and new methods
are uncovered to deal with the issue of fatigue.
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MODULE 1
FATIGUE Introduction 1 Fatigue is a hazard that affects safety,
health and well-being. It presents a considerable risk to safety of
life, property, health, security and protection of the marine
environment. 2 This module provides a general overview of fatigue
and its causes and consequences. This knowledge is important for
developing strategies to reduce the risk of fatigue and related
incidents. 3 It is recommended that all parties become familiar
with module 1 prior to using modules 2 to 6. Fatigue and life on a
ship 4 There is a common misconception that fatigue "comes with the
job"; while not particular to the maritime industry, it is
certainly pervasive within it. Fatigue is a hazard and needs to be
addressed. 5 Fatigue is a problem for all 24-hour-a-day
transportation modes and industries, including the maritime
industry. However, operational aspects associated with the maritime
industry are also more complex than those associated with other
industries. For example, variety of ship-types, the pattern and
length of sea passage, the number of port visits and port
rotations, and the length of time a ship remains in port, all
present unique combinations of potential causes of fatigue. 6 The
demanding nature of shipping means that:
.1 seafarers may be required to work long and irregular hours;
.2 seafarers may spend an extended period of time working and
living away
from home, on a ship that is subject to unpredictable
environmental factors (i.e. changing weather conditions);
.3 the ship is both a seafarer's workplace and their home while
on board; and .4 while serving on board the vessel, there may not
be a clear separation
between work and recreation, which can influence their mental
and emotional well-being.
7 Technology is sometimes seen as a way to improve the
efficiency of work systems. However, technology changes the nature
of work and alters workload, therefore it is important to evaluate
the impact of technological changes on crew workload and
consequently fatigue.
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Causes of fatigue 8 Fatigue is caused by a range of factors, but
is primarily caused by:
.1 lack of sleep, i.e. inadequate restorative sleep; .2 poor
quality of sleep and rest; .3 work/sleep at inappropriate times of
the body clock (circadian rhythm); .4 staying awake for long
periods; .5 stress; and .6 excessive workload (prolonged mental
and/or physical exertion).
9 There are many ways to categorize the causes of fatigue. To
ensure thoroughness and to provide good coverage of most causes,
they have been categorized into five general factors:
.1 seafarer-specific factors;
.2 management factors (ashore and aboard ship);
.3 ship-specific factors;
.4 environmental factors; and .5 operational factors.
Seafarer-specific factors 10 The seafarer-specific factors are
related to lifestyle behaviour, personal habits and individual
attributes. Fatigue varies from one person to another and its
effects are often dependent on the particular activity being
performed. 11 The seafarer-specific factors include the
following:
.1 sleep and rest:
.1 quantity, quality and continuity of sleep;
.2 sleep disorders/disturbances; and .3 recovery
rest/breaks;
.2 body clock/Circadian rhythms; .3 psychological and emotional
factors:
.1 fear;
.2 monotony and boredom; and
.3 loneliness;
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.4 health and well-being:
.1 diet/nutrition/hydration; .2 exercise and fitness; and .3
illness and onset of illness;
.5 stress:
.1 skill, knowledge and training as it relates to the job; .2
personal issues of concern in personal life; and .3 interpersonal
relationships at work or at home;
.6 medication and substance use:
.1 alcohol; .2 drugs (prescription and non-prescription); .3
supplements; and .4 caffeine and other stimulants;
.7 age; .8 shift work and work schedules; .9 workload
(mental/physical); and .10 jet lag.
Management factors (ashore and aboard ship) 12 Management
factors relate to how ships are managed and operated. These factors
can potentially cause stress and an increased workload, ultimately
resulting in fatigue. These factors include:
.1 Organizational factors:
.1 manning policies, levels, and retention; .2 role of riders
and shore personnel; .3 administrative work/reporting/inspection
requirements; .4 economics; .5 duty schedule-shift, overtime,
breaks; .6 company procedures, culture and management style;
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.7 shore-based support; .8 rules and regulations; .9 other
resources; .10 maintenance and repair of the ship; and .11 drill
schedules and training of crew;
.2 Voyage and scheduling factors:
.1 frequency and duration of port calls; .2 time between ports;
.3 routeing; .4 weather and sea condition on route; .5 traffic
density on route; .6 nature of duties/workload while in port and at
sea; and .7 availability of shore leave.
13 Module 2 provides recommended strategies for identifying,
mitigating and controlling fatigue risks due to management factors.
Ship-specific factors 14 These factors include some ship features
that can affect and contribute to fatigue. Some ship design
features affect workload (i.e. automation, equipment design and
reliability), some affect the crew's ability to sleep, and others
affect the level of physical stress on the crew (i.e. noise,
vibration, accommodation spaces, etc.). The following list details
some influential ship-specific factors:
.1 ship design;
.2 level and complexity of automation;
.3 level of redundancy;
.4 equipment design and reliability;
.5 inspection and maintenance;
.6 condition of the ship;
.7 physical comfort in work spaces;
.8 location of quarters;
.9 ship motion; and .10 physical comfort of accommodation
spaces.
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15 Module 5 provides recommended strategies for identifying,
mitigating and controlling fatigue risks due to ship-specific
factors. Environmental factors 16 Environmental factors within
areas in which seafarers live and work (both inside and outside the
ship) may contribute to the onset of fatigue, and impact both sleep
quantity and quality. Environmental factors to consider include
noise and vibration, light, ship motion, temperature and humidity,
and ventilation/air exchange. Long-term exposure to some of the
following may impact a person's health:
.1 Noise: (such as main engines, switchboards, TV and
conversations) affects the ability to fall asleep, causing sleep
loss, or it can alter one's sleep stage or depth of sleep.
.2 Vibration: may affect sleep and fatigue. For example,
alterations in vibration
pattern may keep people awake, keep them from advancing into
deeper sleep, or wake them up.
.3 Light: (such as colour, intensity and exposure timing) is a
complicated
environmental factor. In addition, the use of electronic
displays that emit blue light (such as computer screens,
flat-screen televisions and smartphones) can also influence the
body clock and can delay the onset of sleep, especially when used
prior to bedtime.
.4 Ship motion: depending on the weather and sea conditions,
ship motion
may interfere with sleep, cause motion-induced fatigue (fatigue
caused by the extra energy expended to maintain balance while
moving, especially during harsh sea conditions) and
seasickness.
.5 Temperature and humidity: all excessively hot and cold
conditions will
make an individual feel less alert and generally more fatigued.
It is important that the shipboard temperature and humidity is
controllable as this affects sleep and alertness. For example, the
body sleeps best when the environment temperature is between 18ºC
and 24ºC.
.6 Ventilation/air exchange: in addition to controlling
temperature and
humidity, air quality (e.g. noxious odours or stale air) and
design/placement of the ventilation system may interfere with
sleep.
Operational factors 17 While seafarers, companies,
Administrations and port State authorities are the primary actors,
many other stakeholders may also have an impact on shipboard
operations and workload. Aspects to consider include inspections,
surveys, audits, visits, reporting, security measures and any other
additional tasks to be performed on board. Therefore, other
stakeholders should contribute to the mitigation of fatigue by
considering the impacts of their actions on shipboard operations.
18 Opportunities to mitigate the effects of these factors vary and
will be discussed further in subsequent modules.
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Important basic concepts in understanding fatigue 19 This
section highlights some of the important concepts that provide an
overall understanding about fatigue. The most significant aspects
of fatigue are:
.1 sleep; .2 body clock and the circadian rhythm; .3 time awake;
.4 jet lag; .5 workload; .6 stress; .7 health; and .8 individual
differences.
Sleep 20 Not all sleep has the same quality or provides the same
recuperative benefits. In order to satisfy the needs of the human
body, sleep must have three characteristics to be most
effective:
.1 Quantity: it is generally recommended that a person obtain,
on average, seven to eight hours of good quality sleep per 24-hour
period. To perform adequately and effectively, a person needs the
amount of sleep that produces the feeling of being refreshed and
alert. Alertness and performance are directly related to sleep.
Insufficient sleep will impair alertness. Only sleep can maintain
or restore performance levels.
.2 Quality: sleep is a highly organized sequence of events that
follows a regular
pattern of cycles between light and deep sleep. People need deep
sleep. Deep sleep is a very restorative phase of sleep.
.3 Continuity: sleep quality is dependent upon unbroken cycles
of sleep,
meaning sleep needs to be uninterrupted in order to retain its
restorative value. Six 1-hour naps do not have the same benefit as
one 6-hour period of sleep. The more fragmented the sleep cycle,
the less restorative sleep becomes. This results in continued
feelings of tiredness and often impacts performance and
decision-making. If the time of sleep is out of synchronization
with a person's body clock, it is difficult to sleep properly. It
should be noted that the proportion of time spent in deep sleep
decreases as we get older. Sleep also becomes more fragmented as we
get older.
21 Many factors contribute to sleep disruption and poor sleep
quality; some are within our control while others are not:
.1 environmental factors; .2 food;
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.3 medication and substance use; .4 psychological factors; .5
sleep disorders; and .6 operational factors.
22 Sleep debt is "insufficient accumulated sleep over multiple
consecutive 24-hour periods". For example, if an individual needs
eight hours of sleep per 24-hour period and only obtains six hours,
they have accumulated a sleep debt. Sleep debt will affect an
individual's level of alertness and performance. Long-term sleep
debt may also lead to health problems. Over time, sleep-deprived
individuals may become less aware of just how fatigued they are and
become unable to judge their own level of performance. 23 When
someone is woken up suddenly, the brain can have difficulty
transitioning out of deep sleep. This is known as sleep inertia.
Sleep inertia causes feelings of grogginess and disorientation,
with impaired short-term memory and decision-making, and can last
longer than 30 minutes. Sleep inertia can also occur following
lighter sleep, but it tends to be longer and more disorienting when
someone is woken abruptly out of deeper sleep. Body clock and the
circadian rhythm 24 The time of day in which work takes place is a
key risk factor in determining fatigue. This is because,
independent of prior sleep and wakefulness, humans are biologically
programmed to be active during the day and to sleep at night. 25
Each individual has a body clock, and this clock regulates the
body's circadian rhythm. Our bodies move through various physical
processes and states within a 24-hour period, such as
sleeping/waking, and cyclical changes in body temperature, hormone
levels, sensitivity to drugs, etc. This cycle represents the
circadian rhythm. The body clock is synchronized to the traditional
pattern of daytime wakefulness and night-time sleep. 26 The body
clock makes a person sleepy or alert on a regular schedule whether
they are working or not. In normal conditions, the sleep/wake cycle
follows a 24-hour rhythm; however, the cycle is not the same for
everyone. 27 Independent of other factors, fatigue is most likely,
and when present, most severe, in the early hours of the morning,
coinciding with the strongest drive for sleep. This period
typically occurs between the hours of 3 and 5 a.m. and is commonly
referred to as the window of circadian low (WOCL). 28 In general,
seafarers working through the night may be at a higher risk of
fatigue and have to make additional effort to maintain alertness
and performance. This is supported by maritime studies and
investigations in which fatigue was found to be a contributing
cause in incidents that mainly occurred between midnight and 6 a.m.
This indicates that from a maritime perspective high risk times may
fall between these hours. 29 Apart from the WOCL, another distinct
dip occurs between 3 and 5 p.m. (best known as the post-lunch
dip).
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30 The states of sleep/wakefulness and circadian rhythms
interact in several ways:
.1 The two can work against each other and thereby weaken or
negate each other's effect. For example, a well-rested person is
still affected by a circadian low point; conversely, a person who
is sleep-deprived may feel a momentary increase in alertness due to
a peak in circadian rhythm.
.2 The two can also work in the same direction, thereby
intensifying the effect
they each have on a person's level of alertness. For example,
when someone is sleep-deprived, a circadian low point will further
exacerbate the feeling of sleepiness.
31 For many seafarers, working patterns conflict with their body
clock. Irregular schedules caused by shifting rotations, crossing
time zones, etc. cause the circadian rhythms to be out of
synchronization. As circadian adjustment to a particular pattern of
work and rest is a relatively slow process (only adjust by an hour
or two each day), constant changes impair sleep. Work that requires
seafarers to be awake and working at night or early morning or to
work for extended periods can cause disruptions to the body clock
resulting in increased fatigue. 32 Even though the body clock can
be reset over time, such as when changing times zones for an
extended period, research shows that it cannot be permanently
adjusted to a reversed cycle of work and sleep. Because the body
clock may not adapt fully to altered sleep/wake patterns:
.1 seafarers who work through the night can be expected to be
sleepy and have to make additional effort to maintain alertness and
performance; and
.2 some seafarers may be fatigued at the start of their work
period, as they
adapt to their sleep routine. Time awake 33 How long an
individual is awake affects sleepiness and consequently fatigue
levels. The longer an individual has been awake, the poorer their
performance. In general, the longer a seafarer remains awake, the
stronger the drive for sleep, and the higher the levels of fatigue.
During the first hours awake, the urge to sleep may go unnoticed,
but as the amount of continuous wakefulness approaches 16 hours,
awareness of the pressure to sleep is highly likely. This occurs
sooner if the seafarer is already suffering from sleep debt. 34
Alertness and performance levels begin to decrease after a number
of hours awake, with long duty periods associated with higher
levels of fatigue than shorter duty periods due to extended
wakefulness and demands on attention. In addition, the longer an
individual has continuously been on a task without a break, the
more likely they will be fatigued. Accident rates rise
exponentially after 12 hours of consecutive work, particularly when
working at night. 35 Long work hours are associated with poor
performance, higher injury rates, and poorer safety and/or health
outcomes (both mental and physical). Another important aspect to
consider are work commutes. Many seafarers may be required to
travel or drive long distances to the ship and then have to
work.
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Jet lag
36 Jet lag occurs following long flights through several time
zones. Seafarers crossing time zones to join their ship are exposed
to a sudden change in the day/night cycle causing circadian
disruption. It is a condition that causes fatigue in addition to
sleep deprivation and irritability. The body clock will eventually
adapt to a new time zone; however, depending on the new schedule,
it takes several days to adjust. During the period of adaptation to
the new time zone, common symptoms include wanting to eat and sleep
at times that are out of step with the local routine, problems with
digestion, degraded performance on mental and physical tasks, and
mood changes. It is easier to adjust while crossing from east to
west than from west to east.
Workload 37 Workload refers to the type and intensity of tasks
performed. Fatigue can occur when workload is either very high or
very low. High and low workload may be present in a shipboard work
environment, and are likely to induce fatigue. Fatigue resulting
from workload becomes an increasing concern when combined with long
periods of wakefulness and long duty hours.
.1 High workload: both high physical workload and high mental
workload (such
as tasks with excessive demands on attention) may lead to
fatigue. Examples of high workload routinely experienced on board
ships include, but are not limited to, navigating in congested and
dangerous waters; frequent port calls; navigating in conditions of
poor visibility and/or bad weather; entering and exiting a
port/harbour; having to complete multiple tasks; and tank cleaning
and cargo operations.
.2 Low workload: monotonous tasks, such as monitoring (of
engine-room
displays for example) can result in loss of interest and
boredom, which also increases the effects of fatigue. This can be a
particular problem when conducting bridge or engine monitoring and
vigilance tasks across long periods of time. This can be readily
seen when a person is required to maintain a period of concentrated
and sustained attention, especially during the night (night duty,
for example). People are generally not good at long duration
vigilance tasks. Performance and alertness is further impacted if
vigilance and monitoring tasks need to be carried out during the
night-time hours, specifically between midnight and 5 a.m.
Stress 38 Stress occurs when a person is confronted with an
environment or situation that poses a threat or demand, and the
individual becomes aware of his or her inability to cope or
difficulty in coping with the environment (a feeling of being
overwhelmed). This can result in reduced work performance and
health problems. Stress is influenced by many characteristics of
the work environment or issues with or changes to personal, family,
or home environment. Stress can be caused by a number of factors,
including:
.1 environmental factors (e.g. constant or irregular noise,
vibration, temperatures, weather, ice conditions);
.2 personal circumstances (e.g. family problems, home sickness,
isolation); .3 inadequate restorative sleep; .4 broken or
interrupted sleep or rest periods;
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.5 excessive working hours; .6 intense mental and/or physical
workload; and .7 onboard interpersonal relationships.
39 These stressors, and others, can impact the extent to which a
seafarer is able to acquire sufficient sleep and consequently lead
to fatigue. For example, family aspects that require attention but
are beyond the seafarer's control may lead to short sleep duration
and extended wakefulness. Seafarers may be away from home for
extended periods of time. Loneliness, isolation, family conflict
and concern about family members may provide enough stress to be
considered risk factors. Health 40 Healthy lifestyle choices such
as good physical fitness and a healthy diet have been reported to
reduce fatigue and improve alertness and performance. Conversely,
unhealthy lifestyle choices can negatively impact sleep and
therefore contribute to fatigue.
.1 Nutrition: a poor diet that does not include fresh fruit and
vegetables can contribute to fatigue by adversely affecting a
seafarer's health. In addition, irregular meal times can adversely
affect digestion, which also follows the circadian rhythm.
Digestion is programmed to be most efficient during the day and
much less so at night. Food eaten at night is digested at a slower
rate. This can often lead to feeling bloated or constipated and can
cause heartburn and indigestion. Gastrointestinal upsets are very
common in people who eat outside of traditional meal times. These
upsets can be made worse by drinking tea, coffee or alcohol.
Additionally, when lying down right after eating a large meal, acid
reflux may occur. Night workers are 5 times more likely to get
peptic ulcers than day workers.
.2 Hydration: dehydration is also a factor that contributes to
fatigue. When the
body is low on water, it tries to conserve what it has left. It
does this by reducing activity and making the body relax and slow
down. When relaxed, people have a higher chance of falling asleep.
Being dehydrated can also make people feel light-headed and cause
headaches. In addition to maintaining cognitive function and
alertness, drinking adequate water helps keep the digestive and
circulatory systems operating properly. Water brings healthy
nutrients to cells and carries away toxins.
.3 Exercise and fitness: poor physical fitness adversely affects
overall health
and causes people to tire easily. Exercise speeds up metabolism
and increases blood flow, which helps to keep a person awake.
Exercise also helps the body cope with stress and can help
individuals suffering from depression, a condition that can be
characterized by fatigue. Physical exercise can also help reduce a
person's susceptibility to certain diseases and infections. The
inability to exercise is considered a risk factor because it is a
circumstance that takes away a crew member's ability to increase
physical fitness, enhance sleep, think clearly and manage
stress.
.4 Caffeine and other stimulants: caffeine can be found in
beverages such as
coffee, tea and some soft drinks. Caffeine can improve alertness
and concentration in moderate doses, but it is not a substitute for
adequate sleep and rest. Too much caffeine can have harmful effects
such as increased
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heart rate and blood pressure, and can cause fatigue in some
people. It takes caffeine about 15 to 30 minutes to enter the
body's system, and its physiological effects peak about an hour
after the drug reaches the bloodstream. The effects of caffeine can
vary highly from individual to individual and depend on physical
condition, age, level of sleep debt, frequency of use and time of
day. Generally, caffeine levels drop by half every five or six
hours. Its effects can last long after consumption and may
interfere with needed sleep. Caffeine shortens total sleep time by
preventing sleep. Caffeine consumption can also cause
dehydration.
.5 Alcohol: although alcohol is a central nervous system
depressant, it can
impair the quality of sleep. Alcohol can lead to increased
sleepiness and reduced alertness, even after the alcohol is no
longer detectable. There are also serious health consequences
related to the long-term abuse of alcohol. Many shipping companies
have "zero alcohol tolerance."
.6 Nicotine: nicotine is highly addictive and the dangers to
health are well
documented. Nicotine users generally have more disturbed sleep,
typically taking longer to fall asleep and experiencing more wake
time during a sleep period.
.7 Drugs: it is important for seafarers to be aware of how drugs
and
supplements may affect their health and their sleep-wake cycles.
Drug effects vary not only from person to person, they can also
vary for the same person depending on time of day, mood, tiredness
and the amount of food eaten. In addition, there are other drugs
prescribed for specific ailments that can have sedating side
effects. Some prescription drugs can affect people's ability to
operate machinery (induce sleepiness). They may also interact with
existing fatigue levels and other drugs (including alcohol) and
supplements, further affecting performance. Some over-the-counter
drugs used for pain relief or colds and flu may increase drowsiness
and fatigue-related symptoms.
.8 Supplements: there are now a number of nutritional
supplements, natural
products and energy drinks that are available on the market that
directly influence sleep/wake states. Just because they are sold
over the counter does not mean they are safe or appropriate for
everyone. These products may interact with prescription or
over-the-counter drugs to further affect performance. Individuals
should proactively seek advice and guidance from their healthcare
providers before using these products to learn about their
appropriate use.
.9 Sleep disorders: other health-related aspects are the wide
variety of sleep
disorders, which are known to disrupt the quality of sleep and
make restorative sleep impossible, even when individuals spend
enough time trying to sleep. The most common sleep disorders are
obstructive sleep apnoea, insomnia, restless legs syndrome, shift
work sleep disorder and narcolepsy. Undiagnosed or untreated sleep
disorders can cause sleepiness problems. Sleep disorders pose a
particular risk for seafarers, especially as maritime operations
already expose seafarers to restricted sleep. Large numbers of
individuals suffering from sleep disorders are unaware of and have
not been diagnosed or treated for their disorder.
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.1 Obstructive sleep apnoea (OSA) results in breathing being
interrupted during sleep. Repetitive episodes of non-effective
breathing, very shallow breaths or inadequate breaths lead to
frequent partial arousals from sleep, resulting in ineffective
sleep and sleep debt. OSA is a potentially serious sleep disorder
resulting in excessive daytime sleepiness and can lead to
cardiovascular problems. Sleep apnoea, which may be indicated by
loud snoring with pauses of silence, often goes undiagnosed and
untreated and has been known to be a contributing factor to
incidents in all modes of transportation. Some risk factors include
excessive weight, high body mass index (BMI), high blood pressure,
smoking and diabetes.
.2 Insomnia is the most prevalent sleep disorder and is
characterized
by an inability to fall asleep and/or by waking up during the
night and having difficulty going back to sleep. Long-term insomnia
is more common in women than men and tends to increase with age.
Short-term insomnia may be caused by emotional or physical
discomfort, stress, environmental noise, extreme temperatures or
jet lag, or may be the side effect of medication. Secondary
insomnia may result from a combination of physical or mental
disorders, undiagnosed or uncontrolled sleep disorders and effects
of prescription or non-prescription medications.
.3 Restless legs syndrome (RLS) is a movement disorder that is
often
associated with a sleep complaint. People with RLS have
unpleasant leg sensations and an almost irresistible urge to move
their legs. Symptoms are worse during inactivity and often
interfere with sleep. Sitting still for long periods becomes
difficult; symptoms are usually worse in the evening and night and
less severe in the morning.
.4 Shift work sleep disorder is characterized by insomnia
and
excessive sleepiness affecting people whose work hours overlap
with the typical sleep period. There are numerous shift work
schedules (permanent, intermittent or rotating); consequently, the
manifestations of this disorder are quite variable. Those with
shift work disorder complain more of mood problems such as
impatience and depression, as well as more self-reported health
complaints such as ulcers and substance use.
.5 Narcolepsy is a chronic sleep disorder that usually becomes
evident
during adolescence or young adulthood. The main characteristic
of narcolepsy is excessive and overwhelming daytime sleepiness
(even after adequate night-time sleep). A person with narcolepsy is
likely to become drowsy or to fall asleep at inappropriate times
and places, and in extreme cases during periods of activity.
Daytime sleep attacks may occur without warning and may be
irresistible. In addition, night-time sleep may also be
fragmented.
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Individual differences 41 Individuals respond to fatigue
differently and may become fatigued at different times, and to
different degrees of severity, under the same circumstances. There
are also individual characteristics related to circadian rhythms.
People can be characterized as morning or evening types depending
on the period of the day when they perform at their best. Effects
of fatigue 42 When a person is affected by fatigue, performance on
the job can be significantly impaired. Impairment will occur in
every aspect of human performance (physically, emotionally, and
mentally) such as in decision-making, response time, judgement,
hand-eye coordination and countless other skills. When impairment
due to fatigue, such as impaired memory or poor communication,
coincides with other risks in the environment, incidents can
result. This is evidenced in a number of maritime casualties in
which fatigue was a contributory factor. Maritime studies have also
confirmed the association between fatigue and poor performance. 43
People are poor judges of their own level of fatigue, performance
and decision-making. The following is a sample of fatigue's known
effect on performance:
.1 Fatigued individuals become more susceptible to errors of
attention and memory (for example, it is not uncommon for fatigued
individuals to omit steps in a sequence).
.2 Fatigued individuals will often select strategies that have a
high degree of
risk on the basis that they require less effort to execute.
.3 Fatigue can negatively affect an individual's ability to
identify and respond to stimuli.
.4 Fatigue can also negatively affect problem-solving, which is
an integral part
of handling new or challenging tasks. 44 Particularly dangerous
situations at sea arising from sleep debt are brief, uncontrolled
and spontaneous sleep episodes while working, termed microsleeps.
During a microsleep, the brain disengages from the environment (it
stops processing visual information and sounds). Sleep deprivation,
which is caused by cumulative sleep debt, can make people more
susceptible to microsleeps. The likelihood of microsleeps is even
greater if the individual is on duty during a circadian low. 45 The
range of effects and signs of fatigue can typically be grouped into
three categories: cognitive (e.g. loss of vigilance), physical
(e.g. yawning, micro-sleeps) and behavioural (e.g. irritability,
mood). The table below outlines some of the major symptoms under
each category; however, it is not inclusive. Additionally, many of
these symptoms may be subtle.
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Table 1: Effects of fatigue
COGNITIVE
PERFORMANCE IMPAIRMENT SIGNS/SYMPTOMS
Inability to concentrate Unable to organize a series of
activities Preoccupied with a single task Focuses on a trivial
problem, neglecting more important
ones
Reverts to old but ineffective habits Less vigilant than usual
Decline in ability to solve complex problems Lapses of attention
Difficulty in multitasking
Diminished decision-making ability
Misjudges distance, speed, time, etc. Fails to appreciate the
gravity of the situation Overlooks items that should be included
Chooses risky options Greater indecisiveness
Poor memory Fails to remember the sequence of task or task
elements Difficulty remembering events or procedures Forgets to
complete a task or part of a task Memory lapses
Slowing of cognitive processes
Responds slowly (if at all) to normal, abnormal or emergency
situations
PHYSICAL
PERFORMANCE IMPAIRMENT
SIGNS/SYMPTOMS
Involuntary need to sleep Slow eyelid closures
Droopy eyelids Itchy eye Nodding off Inability to stay awake
Loss of control of bodily movements
Affected speech, e.g. it may be slurred, slowed or garbled, or
hard to find the right words
Feeling heaviness in the arms and legs Clumsiness, such as
increased frequency of dropping
objects like tools or parts
Difficulty with hand-eye coordination skills (such as switch
selection)
Tremors
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Health Issues Headaches Giddiness Rapid breathing Digestion
problems Leg pains or cramps Insomnia Sudden sweating fits Heart
palpitations / irregular heart beats Loss of appetite (and
sometimes an increase in unhealthy
eating habits)
BEHAVIOURAL
PERFORMANCE IMPAIRMENT
SIGNS/SYMPTOMS
Mood change Quieter, less talkative than usual Unusually
irritable Decreased tolerance and anti-social behaviour
Depression
Attitude change Fails to anticipate danger Fails to observe and
obey warning signs Seems unaware of own poor performance More
willing to take risks Ignores normal checks and procedures Displays
a "don't care" attitude Less desire to socialize Increasing
omissions and carelessness Low motivation
46 Sleep debt, over long periods of time (more than two weeks),
has long-term effects on health and clinical illnesses, increasing
the risks of pain, stress, obesity, coronary heart disease,
gastrointestinal disorders and diabetes. Long-term effects also
point to mental health problems such as negative mood states and
depression.
47 Fatigue is known to affect performance and reduce individual
and crew effectiveness and efficiency, decrease productivity, lower
standards of work, and may lead to errors. The instances of
injuries and incidents reportedly related to fatigue within
maritime operations have resulted in great economic, environmental
and human cost. Thus, addressing the risks of fatigue and its
causes is essential.
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ILO and IMO instruments related to fatigue
48 The following IMO instruments contain guidance on
fatigue-related aspects: .1 International Convention on Standards
of Training Certification and
Watchkeeping for Seafarers (STCW), 1978, as amended
.1 Regulation VIII/1 (Fitness for duty) states that "each
Administration shall, for the purpose of preventing fatigue:
.1 establish and enforce rest periods for watchkeeping
personnel and those whose duties involve designated safety,
security and prevention of pollution duties in accordance with the
provisions of section A-VIII/1 of the STCW Code; and
.2 require that watch systems are so arranged that the
efficiency of all watchkeeping personnel is not impaired by
fatigue and that duties are so organized that the first watch at
the commencement of a voyage and subsequent relieving watches are
sufficiently rested and otherwise fit for duty."
.2 Regulation VIII/2 (Watchkeeping arrangements and principles
to be
observed) states that "Administrations shall direct the
attention of companies, masters, chief engineer officers and all
watchkeeping personnel to the requirements, principles and guidance
set out in the STCW Code which shall be observed to ensure that a
safe continuous watch or watches appropriate to the prevailing
circumstances and conditions are maintained on all seagoing ships
at all times."
.3 In addition, part A of the STCW Code sets minimum periods
and
frequencies of rest and requires that watch schedules be posted
where they are easily accessible.
.2 International Safety Management (ISM) Code: This Code
introduces
safety management requirements on ship companies to assess all
identified risks (both ashore and afloat) that affect safety (to
ship and personnel) and environment and establish appropriate
safeguards. The fatigue-related requirements include the
requirement for the company to:
.1 develop, implement and maintain a safety management
system
(section 1.4); .2 ensure that each ship is manned with
qualified, certificated and
medically fit seafarers in accordance with national and
international requirements and is appropriately manned in order to
encompass all aspects of maintaining safe operations on board
(paragraph 6.2);
.3 ensure necessary shipboard support is provided so that
the
master's duties can be safely performed (paragraph 6.1.3); and
.4 provide familiarization and training for shipboard personnel
(paragraphs 6.3, 6.4 and 6.5).
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.3 Principles of minimum safe manning (resolution A.1047(27)):
This resolution provides guidelines for determining minimum safe
manning. In particular in ensuring "fitness for duty", paragraph
1.4.2 of annex 2 states that "in determining the minimum safe
manning of a ship, consideration should also be given to the
capability of the master and the ship's complement to coordinate
the activities necessary for the safe operation and for the
security of the ship and for the protection of the marine
environment."
.4 Fatigue factors in manning and safety (resolution A.772(18)):
This
resolution provides a general description of fatigue and
identifies the factors of ship operations which may contribute to
fatigue.
49 The following ILO instrument contains guidance on
fatigue-related aspects: .1 Maritime Labour Convention (MLC), 2006.
Relevant aspects of the MLC
include, but are not limited to:
.1 Regulation 2.3: To ensure that seafarers have regulated hours
of work or hours of rest.
.2 Regulation 2.4: To ensure that seafarers have adequate leave.
.3 Regulation 2.7: To ensure that seafarers work on board ships
with
sufficient personnel for the safe, efficient and secure
operation of the ship.
.4 Regulation 3.1: To ensure that seafarers have decent
accommodation and recreational facilities on board. .5
Regulation 3.2: To ensure that seafarers have access to good
quality food and drinking water provided under regulated
hygienic conditions.
.6 Regulation 4.3: To ensure that seafarers' work environment
on
board ships promotes occupational safety and health. References
1 Allen, P., Wadsworth, E., and Smith, A., (2008). Seafarers'
fatigue: a review of the
recent literature. International Maritime Health, 591(1-4): p.
81-92. 2 Allen, P., Wellens, B. T., McNamara, R., and Smith, A.
(2005). It's not all plain sailing.
Port turn-arounds and seafarers' fatigue: A case study in
Contemporary Ergonomics. Hatfield, UK.
3 American Academy of Sleep Medicine, (2014). International
Classification of Sleep
Disorders. 3rd ed. ICSD-3. Winchester, IL: AASM. 4 Belenky, G.,
Wesensten, N., Thorne, D. R., Thomas, M. L., Sing, H. C., Redmond,
D.
P., Russo, M. B., and Balkin, T. J., (2003). Patterns of
performance degradation and restoration during sleep restriction
and subsequent recovery: a sleep dose-response study. Journal of
Sleep Research, 12(1-12).
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5 Carotenuto, A., Molino, I., Fasanaro, A. M., and Amenta, F.,
(2012). Psychological stress in seafarers: A review. International
Maritime Health, 63(4): p. 188-94.
6 Caruso, C. C., Bushnell, T., Eggerth, D., Heitmann, A.,
Kojola, B., Newman, K., Rosa,
R. R., Sauter, S. L., and Vila, B., (2006). Long Working Hours,
Safety, and Health: Toward a National Research Agenda. American
Journal of Industrial Medicine, 49: p. 930-942.
7 Costa, G., (1996). The impact of shift and night work on
health. Applied Ergonomics,
27(1): p. 9-16. 8 Dinges, D. F., Pack, F., Williams, K., Gillen,
K. A., Powell, J. W., Ott, G. E., Aptowicz,
C., and Pack, A. I., (1997). Cumulative sleepiness, mood
disturbance, and psychomotor vigilance performance decrements
during a week of sleep restricted to 4-5 hours per night. Sleep,
20: p. 267.
9 European Union, (2012). Project Horizon – a wake-up call,
European Commission,
Seventh Framework Programme p. 32. 10 Folkard, S. and Tucker,
P., (2003). Shift work, safety and productivity. Occupational
Medicine, 53: p. 95-101. 11 Folkard, S., (2008). Do permanent
night workers show circadian adjustment? A
review based on the endogenous melatonin rhythm. Chronobiol Int,
25: p. 215-224. 12 Grech, M. R., Horberry, T., and Koester, T.,
(2008). Human Factors in the Maritime
Domain. CRC Press. Boca Raton. 13 Härmä, M., (2006). Workhours
in relation to work stress, recovery and health. Scand
J Work. 14 Härmä, M., Partinen, M., Repo, R., Sorsa, M., and
Siivonen, P., (2008). Effects of 6/6
and 4/8 watch systems on sleepiness among bridge officers
Chronobiology International, 25(2): p. 413-423.
15 Houtman, I., Miedema, M., Jettinghoff, K., Starren, A.,
Heinrich, J., Gort, J., Wulder,
J., and Wubbolts, S., (2005). Fatigue in the shipping industry,
TNO: Hoofddorp. 16 Lützhöft, M., Dahlgren, A., Thorslund, B.,
Kircher, A., and Gillberg, M., (2010). Fatigue
at sea: A field study in Swedish shipping. American Journal of
Industrial Medicine, 53(7): p. 733-40.
17 Maritime Accident Investigation Branch, (2004). Bridge
Watchkeeping Safety Study,
MAIB. 18 National Sleep Foundation. (2015.How Much Sleep Do We
Really Need? [cited 2015
20 April]. Available from:
http://www.sleepfoundation.org/article/how-sleep-works/how-much-sleep-do-we-really-need
19 Oldenburg, M., Hogan, B., and Jensen, H. J., (2013).
Systematic review of maritime
field studies about stress and strain in seafaring.
International archives of occupational environmental health, 86(1):
p. 1-15.
http://www.sleepfoundation.org/article/how-sleep-works/how-much-sleep-do-we-really-needhttp://www.sleepfoundation.org/article/how-sleep-works/how-much-sleep-do-we-really-need
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20 Phillips, R. O., (2014). An assessment of studies of human
fatigue in land and sea transport., in Fatigue in Transport Report
II, Institute of Transport Economics (TØI). Oslo.
21 Phillips, R. O., Nævestad, T. O., and Bjørnskau, T., (2015).
Transport operator fatigue
in Norway: literature and expert opinion, in Fatigue in
Transport Report III, Institute of Transport Economics: Oslo.
22 Pilcher, J. J. and Huffcutt, A. I., (1996). Effects of sleep
deprivation on performance:
a meta-analysis. Sleep, 19(4): p. 318-26. 23 Rosa, R. R.,
(2012). Long work hours, fatigue, safety, and health, in The
handbook of
operator fatigue, Matthews, G., Desmond, P. A., Neubauer, C.,
and Hancock, P. A., Editors. Ashgate Publishing Ltd.: Surrey.
24 Starren, A., M., van Hooff, M., Houtman, I., Buys, N.,
Rost-Ernst, A., Groenhuis, S.,
and Dawson, D., (2008). Preventing and managing fatigue in the
Shipping industry, TNO: Hoofddorp.
25 United States Coast Guard, (2005). Crew Endurance Management
Practices:
A Guide to Maritime Operations, Marine Safety and Environmental
Protection: Washington, DC.
26 van der Hulst, M., (2003). Long workhours and health. Scand J
Work Environ Health,
29(3): p. 171-88. 27 Wadsworth, E. J. K., Allen, P. H., Wellens,
B. T., McNamara, R. L., and Smith, A. P.,
(2008). Patterns of fatigue among seafarers during a tour of
duty. American Journal of Industrial Medicine, 49(10): p.
836-844.
28 Williamson, A., Lombardi, D. A., Folkard, S., Stutts, J.,
Courtney, T. K., and Connorf,
J. L., (2009). The link between fatigue and safety. Accident
analysis and Prevention, 43(2011): p. 498-515.
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MODULE 2
FATIGUE AND THE COMPANY
1 Module 2 contains guidance for the company in assessing,
mitigating and managing the risk of fatigue in operational
environments. Is fatigue an important issue in shipboard
operations?
2 Fatigue has been recognized as an important occupational
health and safety issue for seafarers. Fatigue has the potential to
greatly increase the risk of incidents and injuries in the work
place. It disrupts circadian rhythms and results in digestive
problems, confusion, lethargy, respiratory problems, depression and
irritability. Fatigue adversely affects seafarer performance. It
diminishes attentiveness and concentration, slows physical and
mental reflexes and impairs rational decision-making capability. 3
Research has established a clear link between fatigue and accidents
at sea. Clearly, addressing the issue of fatigue should have a
positive effect on personnel safety and has the potential to cut
costs for the company by reducing injury and physical damage to
high-value assets and the environment. 4 Fatigue poses a risk to
any position on board, but especially those that have critical
safety and security responsibilities. Should an individual fail to
carry out an allotted task due to fatigue, the crew runs the risk
of a safety or security incident. Any risk management strategy must
focus on mitigating the potential for such hazards to arise by
addressing the causes of fatigue. Systems and work procedures
should be critically examined to engineer out design deficiencies
that could contribute to fatigue. The company should provide an
adequate level of support for managing the risks of fatigue at both
the organizational and operational levels.
What elements of fatigue can the company influence? 5 While it
is not possible for the company to regulate and oversee the
sleeping habits of every seafarer on every ship, it is within its
capability to mitigate the risks of fatigue through ship design,
operational and manning policies. The Principles of minimum safe
manning (resolution A.1047(27)) provides for an assessment of the
tasks, duties and responsibilities of the ship's complement to
ensure that manning levels are adequate at all times to meet all
conditions and requirements including meeting peak workload
situations and emergency conditions. Hours of rest are presently
controlled by a prescriptive formula set out in chapter VIII of the
International Convention on Standards of Training, Certification
and Watchkeeping for Seafarers (STCW) 1978, as amended. Managers
should be aware (when applying these hours of rest) that
considering the effects of circadian rhythm and sleep debt is
important for ensuring that rest periods are of high quality. It
also cannot be too highly stressed that rest means rest, not
substituting a different form of work. This should be supported by
appropriate manning, resources, processes and policies, so that
fatigue risks can be managed in a way that supports safe, compliant
and productive operations. Importantly, fatigue risk control
measures forming part of the company support should:
.1 identify and assess fatigue risks; .2 assess operational
workload requirements in accordance with the Principles
of minimum safe manning (resolution A.1047(27));
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.3 ensure that manning and resources are adequate and available
for assessed workload requirements and to conduct all ship
operations safely;
.4 ensure company-wide awareness of the risk of fatigue; and .5
ensure a healthy shipboard environment. 6 Figure 1 below provides a
framework to assess the hazards associated with fatigue and
different strategies to mitigate the risk of fatigue.
Figure 1: Framework to mitigate the risk of fatigue
7 Companies' records of hours of work and rest are generally
assessed against regulatory requirements. Planning tools are
available that take into account the circadian rhythm. The use of
such planning tools may assist companies in doing the following: .1
Analyse planned work routines to ascertain the risk of fatigue. .2
Monitor work hours on board the ship to determine whether or not
the risk of
fatigue is increasing as a result of the work arrangements or
from any variations that may have occurred.
.3 Analyse and compare information related to hours of work to
determine the
effectiveness of employed routines, compared to other
alternatives. 8 It is important that companies adopt a fatigue
mitigation and control strategy that is tailored to the individual
operational requirements.
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How can the company ensure that fatigue prevention is practised
on board? 9 The company should consider the following: .1 ISM Code
requirements for clear, concise guidance on operational
procedures on board;
.2 ensure adequate resources, including manning levels;
.3 promote a safety reporting culture with open communication
and no fear of reprisal;
.4 the need for joining seafarers to be adequately rested before
assuming duties;
.5 schedule time for proper handover on crew change;
.6 voyage length, time in port, length of service and leave
ratios;
.7 multicultural issues; language barriers, social, cultural and
religious isolation;
.8 interpersonal relationships, stress, loneliness, boredom,
social deprivation and increased workload as a result of small crew
numbers;
.9 provision for shore leave and onboard recreation, family
communication;
.10 watchkeeping arrangements;
.11 job rotation, if practicable;
.12 adequate sleeping berths and accommodation;
.13 adequate quality and quantity of food for proper
nutrition;
.14 read other modules of these guidelines for additional
potential managerial mitigation tools; and
.15 modification of present ship design or future designs, if
necessary. 10 Fatigue training and awareness are essential
components. The company should ensure all personnel have
appropriate training. This includes shore-based personnel whose
decisions may impact on the management of fatigue (such as those
involved in resource planning, including ship manning levels, and
duty scheduling decisions) and fatigue-related processes. This is
important, as their decisions potentially affect fatigue levels of
seafarers and consequently shipboard safety. 11 Initial
fatigue-related training should establish a common level of
understanding among seafarers and shore-based personnel about the
dynamics of sleep loss and recovery, the effects of the body clock
on circadian rhythms, the influence of workload, and the ways in
which these factors interact with operational demands to produce
fatigue (covered in module 1). In addition, it is useful for all
seafarers to have information on how to manage their personal
fatigue and sleep issues (covered in module 3). 12 This process, as
with any other training, should be ongoing in nature. Hence,
training should be conducted on an initial and recurrent basis. The
interval between training should be determined by the company,
given their operational characteristics and training needs
analysis.
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13 Promoting a safety reporting culture is necessary. The
company should ensure that processes are in place to provide
seafarers with the opportunity to report situations when the
seafarer has been unable to obtain adequate sleep or feels at risk
of making fatigue-related errors, specifically if conducting safety
critical tasks. This process should allow for open communication
and reporting between seafarers, their supervisors and the company,
and should prohibit any action directed against a seafarer for such
communications or reports. Adequate resources (including ship
manning levels) 14 Adequate resources, including manning, is one of
the primary determinants of seafarers' duty hours, workload, duty
scheduling, average time off duty, and other key factors that can
have an influence or elevate fatigue. The company should ensure
that adequate resources are available with a need to proportionally
balance varying work and task demands and deal with unexpected
surge to reduce the risk of fatigue across shipboard operations. 15
Manning levels should match the operational workload on board the
ships and this workload should be managed efficiently. Operational
workload is determined through an assessment by the company. 16
Although the master is responsible for managing the ship and its
crew, the company should ensure that the master is adequately
supported and resourced to conduct shipboard duties and operations
safely and effectively. 17 Effective operational planning is
critical to ensuring adequate resources, including manning, are
available at all times so that operational and other demands placed
on the ship and its crew can be managed safely and effectively.
Planning should account for: .1 varying work and task demands
within and across days, e.g. amount of time
the ship is travelling through confined and congested waters and
less confined open waters;
.2 trading patterns, i.e. number of port calls – the more port
calls the higher the
workload; .3 planning for disturbances, such as weather, ship
movement in port, port entry
and exit delays and port surveys and inspections; .4 ensuring
adequate manning is available to cover planned and unplanned
aspects such as training, illnesses, injuries and sickness; and
.5 ensuring company commercial obligations or interests do not
impinge on or
affect safety in any way.
18 The company should consider strategies to deal with periods
of high workload and to manage this accordingly. Appropriate
strategies may include the following: .1 The allocation of crew
numbers to peak times and demands is a fundamental
factor in minimizing the exposure to risks associated with
extended duty hours. Numbers and types of seafarers should be
scheduled based on predictable operational demands to account for
daily, weekly and monthly operational trends.
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.2 Ensure the master is well resourced and supported to carry
out all shipboard tasks safely and to allow for unexpected surge
and overriding operational conditions.
.3 Ensure there are adequate resources, including manning,
available to
complete shipboard tasks safely without placing excessive
demands on seafarers.
.4 Augment with shore-based support or additional rest when the
ship is in port,
such as during loading and unloading and port inspections, to
ensure shipboard crew obtain adequate time off for rest and sleep
and are fit for duty when the ship leaves port.
.5 Provide shipboard administrative support or a means for
relieving the burden
associated with paperwork and related administrative tasks. .6
Where practicable, provide remote support to shipboard crew in
areas such
as paperwork, loading/unloading calculations.
.7 Utilize other crewing concepts, such as the use of port
captains and/or shore-based crew.
.8 Plan arrival and departures (tides in ports, delays due to
weather, pilotage
boarding, etc.) to take into account adequate sleep and rest. 19
An important aspect that needs to be mentioned is that of
"overriding operational conditions". In accordance with section
B-VIII/1 of the STCW Code "overriding operational conditions"
should be construed to mean only essential shipboard work which
cannot be delayed for safety, security or environmental reasons or
which could not reasonably have been anticipated at the
commencement of the voyage. This means that they should not be
occurring on a regular basis. Planning, using risk assessment tools
and operational experience, can foresee these potential disruptions
or delays, e.g. weather, port inspections, traffic congestion
during departure/arrivals and illness of seafarers. Healthy
shipboard environment 20 Seafarers are required not only to work
but also to live on board a ship. Hence, ensuring a healthy
shipboard environment is crucial to minimizing the risks of
fatigue. The most important aspects should include: .1 Healthy
eating: healthy nutritious food is available and served on board
and
crew afforded unlimited access to drinking water. .2 Healthy
sleep: the shipboard sleeping environment should provide for
comfortable and good quality sleep (bedding, pillows,
mattresses, adequate light management, etc.).
.3 Exercise: adequate exercise facilities are provided (such as
well-designed
and equipped training facilities and outside spaces), to ensure
seafarers can maintain a healthy lifestyle on board.
.4 Stress: adequate shipboard measures are in place to recognize
and ensure
adequate support to seafarers suffering from stress.
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21 Furthermore, initial ship design plays a part in ensuring a
healthy operational environment (see module 5). Adequate sleep
opportunity 22 Effective fatigue management is predominantly about
ensuring that seafarers are provided with adequate sleep
opportunity. 23 It is not correct to assume that a given rest
period from duty will provide a given level of sleep and hence
recovery. The length of the rest period is only one key factor. The
relationship between the recovery value of off-duty periods and the
actual amount of sleep obtained in a shipboard environment is
increasingly complex. As highlighted in module 1, sleep quantity
and quality (and its restorative value) depends on going through
uninterrupted sleep. The more sleep is fragmented by waking up, the
less restorative value sleep has in terms of how seafarers feel and
function when they are on duty. 24 Shipboard-related factors that
affect sleep include the design of duty schedules, i.e. length and
timing of duty periods, length and timing of breaks within and
between a duty period, and the environment, e.g. heat, humidity,
noise, vibration, lighting levels, ship routines, diet. These can
all have negative effects on the amount of time seafarers are
allocated for sleep in a 24-hour period. Duty scheduling and
planning 25 Duty scheduling and planning is a key factor in
managing fatigue. Hence, the company should be responsible for
ensuring duty schedules provide adequate opportunity for sleep. 26
Companies must, at the very least, be in compliance with STCW
regulation VIII/1. 27 From a practical perspective, it is important
to determine whether a given duty schedule, on average, enables
adequate sleep opportunity. There are seven primary duty schedule
considerations that should be taken into account when scheduling.
They are: .1 Work hours (work periods): as indicated in module 1,
as the length of a
given period of work increases, the subsequent sleep opportunity
decreases. Research has demonstrated that, apart from a reduction
in performance, extended hours of work are also associated with
reduced individual well-being, reduced organizational commitment
and poor health outcomes. Administrative work, shipboard drills,
training, ship loading and unloading tasks are all tasks that may
affect seafarers' opportunities to gain adequate sleep. These
factors in turn have been linked to declining levels of
productivity and safety.
.2 Rest hours (rest periods) between work periods: this is the
length of time
off between work periods and should reflect the fact that
seafarers do not simply fall asleep as soon as they are off duty
and wake just before they go back on duty. Seafarers, like
shore-based workers, have many activities and responsibilities to
manage between work periods such as eating, showering, socializing
with other crew, relaxing, studying and writing to and
communicating with family members and friends back home. Fatigue
increases as the number of rest hours decrease; therefore rest
hours should provide for adequate sleep opportunity, time to
complete those other tasks noted above, be adaptable to the
individual circadian rhythm and account for
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the effects of sleep inertia after waking. Hence, the interval
between two successive work periods should allow sufficient time to
obtain adequate sleep before the start of the next work period.
.3 Night watches or work: as indicated in module 1, seafarers
working during
night-time, specifically during the circadian low, can
experience severe performance degradation initially. If the
seafarer maintains a regular schedule they may adapt over time.
However, it is important to provide those seafarers working during
night-time with a good sleeping opportunity and environment during
the day.
.4 Short rest breaks within work periods: short rest breaks
benefit
performance and help maintain alertness. As indicated in module
1, one of the most important determinants of fatigue is "time on
task". Frequent short breaks are associated with performance
benefits and result in better fatigue management when the timing of
rest is at the discretion of the individual. While it is recognized
that this may not always be feasible in a shipboard environment, it
should be noted that the "time on task" effect can also be reduced
during the work period by task rotations/substitutions.
.5 Naps: naps are an effective countermeasure to fatigue,
exhaustion from long
work hours and restricted sleep. Whether before an anticipated
short night's sleep or after, brief naps improve performance and
alertness, and delay fatigue-induced performance degradation.
Overall, research has shown that the benefits of controlled napping
outweigh the potential risks associated with sleep inertia.
.6 Recovery sleep: the provision for sufficient recovery time
following periods
of sleep debt is important. It should be noted that provision of
minimum rest periods may not sufficiently acknowledge the critical
role that the circadian rhythm plays in the rate at which fatigue
accumulates and the rate at which people recover. To work safely
across a given duty and to then return to the next work period
sufficiently recovered requires that the seafarer obtains
sufficient quantity and quality of sleep between work periods.
Sleep opportunities during the circadian low are preferable because
sleep that occurs during the circadian low provides the most
recuperative value.
.7 Reset breaks: as the risk of fatigue increases over
successive work days of
sleep debt, it seems logical that some "recovery" must take
place over spans of rest days. This is typically an issue at sea as
seafarers are exposed to potentially arduous duty schedules over a
long period of time (in excess of seven days, sometimes months on
end) without the possibility of a reset break. It is recognized
that in a shipboard environment this is likely not practical;
however, this may be a factor to consider when determining crew
rotation.
28 Companies should consider napping and short break policies to
manage fatigue if practicable. 29 Companies should also acknowledge
impairment through sleep inertia when planning tasks and
activities, giving adequate time for seafarers to be alert before
performing critical tasks, when possible.
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Tools to assess fatigue in scheduling 30 The planning of duty
schedules based on fatigue science as well as operational
requirements permits predictive identification of fatigue hazards.
This assists in allocating adequate rest periods that provide
sufficient sleep opportunity. 31 There are useful additional tools
for the mitigation and control of fatigue such as: .1 fatigue risk
assessment tools: the risk level of a specific duty schedule
may
be assessed via a fatigue risk score; and .2 fatigue predictive
software tools: models and related software to predict
fatigue levels for specific operations can be useful additional
tools for the management of fatigue risks, as mentioned in
paragraph 7.
32 Such tools should not be used in isolation nor be the main
driver for duty scheduling decisions, as they are not sufficient to
determine the full extent of fatigue-related risk. They should
always be supported by other operational data. Their main purpose
should be limited to identifying potentially fatigue-inducing duty
schedules or scheduling hot spots and allow for better decisions in
the selection of duty schedules. This is because numerous
unforeseen circumstances can cause changes to planned schedules,
e.g. weather conditions, unexpected technical problems or
seafarers' illnesses. Seafarer fatigue is the result of what is
actually worked, not what is planned. Thus another proactive
approach for identifying fatigue hazards is to analyse actual duty
schedules in operation. Workload management 33 As discussed in
module 1, mental and physical demands of work can contribute to a
seafarer becoming impaired by fatigue in a number of ways.
Concentrating for extended periods of time, performing repetitious
or monotonous work, and performing work that requires continued
physical effort can increase the risk of fatigue. Mental fatigue
and physical fatigue are different and a seafarer can experience
them at the same time. It is important to be aware of a seafarer's
optimal level of workload and stress, and to have realistic
attitudes towards these. Understanding that different people react
differently to stressful situations (such as emergencies, family
problems at home, job-related) is critical for effective
interventions. Hence, the use of effective communication with
seafarers and monitoring and observing any behaviours that may
indicate a change to a seafarer's fatigue as a result of workload
is important (see fatigue signs and symptoms in module 1) . 34
Typical techniques for managing workload while on duty include
prioritization of tasks, task delegation, task rotation, crew
rotation and task shedding. A list of risk mitigation strategies
that should be used in managing workload may include: .1 Carefully
considering task design according to the workload and the
available resources, including manning. .2 Reducing the amount
of time seafarers need to spend performing sustained
physically and mentally demanding work (e.g. tank cleaning,
navigation through congested waters).
.3 Managing workload and work-pace change caused by
machinery
breakdowns and planned and unplanned sicknesses and
illnesses.
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.4 Where practicable, minimizing routine and administrative
tasks or redesigning them to ensure seafarers can focus on core
duties in their working time.
.5 Minimize repetitive or monotonous tasks by using task
rotation, where
practicable. .6 Where practicable, defer non-urgent work to
allow appropriate rest and
recovery if necessary. Work and living environment 35 The work
and living environment is important for ensuring adequate
opportunity for sleep and should be considered. Because good
quality sleep is critical, companies should develop procedures to
minimize interruptions to seafarers' sleep. Opportunities for
implementing countermeasures in this area vary from shipboard
environmental, procedural to operational changes. For example, most
environmental aspects such as noise can be better addressed during
ship design (see module 5). However, there are control measures
that the company can implement to assist in reducing noise levels
in the sleeping environment. 36 Environmental, procedural and
operational measures may also range from low-cost solutions, such
as porthole blinds and door baffles, to high-cost solutions, such
as refitting the ship exhaust or air conditioning systems. 37
Operational and procedural changes may include developing napping
policies or defining blocks of time (sleep opportunities) during
which seafarers are not contacted except in emergencies. These
protected sleep opportunities need to be known to all relevant
personnel. Depending on the situation, changes should be made to
those areas that will have the most impact, and following
evaluation, consideration to other changes can then be made. 38
Environmental control measures may include, but are not limited to:
.1 adequate facilities for rest, sleep and meal breaks and other
essential
requirements, such as bathroom facilities and personal storage;
.2 making sleeping areas darker, quieter and more comfortable and
increasing
lighting in certain areas of the ship, such as: .1 providing a
dark sleeping atmosphere using blackout blinds for
portholes or berths in sleeping spaces; .2 installing insulation
baffles over cabin door louvres; .3 improving air conditioning
(ambient temperature) and air flow; and .4 supplying good quality
and comfortable bedding such as mattresses
and pillows; .3 making sleeping spaces, including their
location, a priority in retrofitting and
new ship construction; and .4 ensuring adequate personal storage
space is available for seafarers'
personal effects.
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39 Procedural and operational control measures may include, but
are not limited to: .1 increasing access to healthier food choices
by ensuring nutritious food is
served on board; .2 providing information and advice on healthy
eating and physical well-being;
.3 making exercise equipment and facilities available to
seafarers;
.4 providing and maintaining a quiet atmosphere for sleep;
develop a "do not disturb" policy for sleeping seafarers;
.5 where practicable, calls for drills should be conducted in a
manner that minimizes the disturbance of rest periods as they can
be extremely disruptive;
.6 putting in place short breaks within duty periods, including
napping policies;
.7 ensuring ship routines such as meal times are commensurate
with seafarer working schedules; this includes providing personnel
working at night with appropriate meal choices;
.8 providing access to counselling services to assist in any
issues arising from the disruption to individual, family or social
patterns and shipboard-related aspects; implement a consistent
stress management programme;
.9 have a policy in place to support seafarers experiencing
elevated levels of workload;
.10 if possible, avoid assigning seasick and ill seafarers
shipboard work;
.11 if possible, provide all seafarers with shipboard phone,
internet and email access; and
.12 if possible, ensure that maintenance work does not disrupt
personnel
sleeping. Adequate sleep obtained 40 Given that sleep loss is a
primary contributor to fatigue, the company should determine
whether adequate sleep is obtained. 41 Situations may arise where a
seafarer is provided with an adequate sleep opportunity, but they
may not get adequate sleep. Hence, while an adequate sleep
opportunity provides an indication of the quantity of sleep likely
to be obtained, it is important to know whether adequate sleep has
actually been obtained. Seafarers should be provided with the
opportunity to report situations when they have been unable to
obtain adequate sleep or feel at risk of making fatigue-related
errors without repercussions. 42 In general, seafarers are
responsible for using adequate sleep opportunity appropriately, so
they are alert and capable of performing assigned shipboard work
safely. However, there are a number of reasons why seafarers may
not obtain adequate sleep. The aspects mentioned below can all
affect the amount and quality of sleep obtained: .1 a seafarer
working during the night may have difficulty getting quality
sleep;
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.2 a seafarer upon joining the ship may experience difficulty
adjusting to the sleep schedule;
.3 a seafarer travelling for an extended time to the ship should
not be required
to report to work until adequate rest is obtained; .4
undiagnosed and untreated sleep disorders as highlighted in module
1; .5 emotional stress; .6 the sleeping environment (comfort,
noise, darkness, ship motion, privacy,
room location) may not allow for adequate sleep; .7 the type of
food consumed; .8 medication or use of
prescribed/over-the-counter/natural remedies; .9 consumption of
stimulants such as caffeine and amphetamines; and .10 use of
personal electronic devices before sleep, which may delay the
onset
of sleep and not allow adequate sleep to be obtained. 43
Regardless of the circumstances causing insufficient or poor
quality sleep, these should preferably be identified through
proactive measures and treated as a potential shipboard hazard.
What rules and regulations are in place to prevent and deal with
fatigue (international, national and company)? 44 Reference is made
to the instruments mentioned in module 1. References 1 Akerstedt,
T., Anund, A., Axelsson, J., and Kecklund, G., (2014).
Subjective
sleepiness is a sensitive indicator of insufficient sleep and
impaired waking function. Journal of Sleep Research, 2014(23): p.
242-254.
2 Dawson, D., Noy, Y. I., Härmä, M., Åkerstedt, T. and Belenky,
G., Modelling fatigue
and the use of fatigue models in work settings, Accident
Analysis & Prevention, Vol. 43, Issue 2 (March 2011), pp.
549–564.
3 Dawson, D. and McCulloch, K., (2005). Managing fatigue: It's
about sleep. Sleep Med
Rev, 9(5): p. 365-380. 4 Gander, P., Hartley, L., Powell, D.,
Cabon, P., Hitchcock, E., Mills, A., and Popkin, S.
(2011). Fatigue risk management: Organizational factors at the
regulatory and industry/company level. Accident analysis and
Prevention, 43(2): p. 573-590.
5 Grech, M. R. (2016) Fatigue Risk Management: A Maritime
Framework, International
Journal of Environmental Research and Public Health, Vol. 13,
No. 2 (2016), pp. 175-184. 6 Johnson, J. V. and Lipscomb, J.,
(2006). Long Working Hours, Occupational Health
and the Changing Nature of Work Organization. American Journal
of Industrial Medicine, 49: p. 921-929.
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7 Philips, R. (1998). Fatigue Among Ship's Watchkeepers: A
Qualitative Study of Incident at Sea Reports in Managing Fatigue in
Transportation: 3rd Fatigue in Transportation Conferences,
Fremantle, Western Australia: Elsevier.
8 Rosa, R. R., (2012). Long work hours, fatigue, safety, and
health, in The handbook of
operator fatigue, Matthews, G., Desmond, P. A., Neubauer, C.,
and Hancock, P. A., Editors. Ashgate Publishing Ltd: Surrey.
9 Tucker, P., (2003). The impact of rest breaks upon accident
risk, fatigue and
performance: a review. Work and Stress, 17(2): p. 123-137. 10
Tucker, P. and Folkard, S., (2012). Work Scheduling, in The
handbook of operator
fatigue, Matthews, G., Desmond, P. A., Neubauer, C., and
Hancock, P. A., Editors. Ashgate Publishing Ltd: Surrey.
11 Williamson, A. and Friswell, R., (2011). Investigating the
relative effects of sleep
deprivation and time of day on fatigue and performance. Accident
analysis and Prevention, 43(3): p. 690-697.
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MODULE 3
FATIGUE AND THE SEAFARER 1 Module 3 contains practical
information intended for the seafarer (master, officers, ratings
and all other shipboard personnel) working on ships. Prior to
reviewing this module, it is strongly recommended that all
seafarers become familiar with module 1 (Fatigue) first.
Management-level seafarers (master and officers) should also become
familiar with module 2 (Fatigue and the company). 2 Although the
company is primarily responsible for creating a work and living
environment that minimizes fatigue-related risks, seafarers are
responsible for ensuring that time available for rest and sleep is
used appropriately and that their behaviour does not create or
increase risk. 3 The maritime industry operates a variety of work
schedules in a wide range of operational environments, which means
that at some point seafarers are likely to experience fatigue.
Fatigue affects all individuals, regardless of skill, rank,
knowledge or training. How to recognize fatigue (signs/symptoms)? 4
Fatigued individuals are poor judges of their own level of fatigue
and performance because fatigue affects their ability to make
judgements or solve complex problems. 5 Fatigue-related signs and
symptoms are often divided into three categories: cognitive,
physical and behavioural (see table 1 in module 1). Seafarers may
recognize some of these in others and, with time, lessons can be
learnt to identify some within themselves. These signs and symptoms
of fatigue may be used to identify an individual's level of
alertness. 6 Some of the more apparent signs and symptoms include:
.1 cognitive:
.1 focuses on a trivial problem, neglecting more important ones;
.2 slow or no response to normal, abnormal or emergency situations;
.3 lapses of attention; .4 poor judgement of distance, speed, time,
etc.; .5 forgets to complete a task or part of a task; and .6
difficulty in concentrating and thinking clearly.
.2 physical:
.1 inability to stay awake (an example is head nodding or
falling asleep involuntarily);
.2 difficulty with hand-eye coordination skills (such as
switch
selection);
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.3 speech difficulties (it may be slurred, slowed or garbled);
.4 increased frequency of dropping objects like tools or parts; and
.5 digestion problems;
.3 behavioural:
.1 decreased tolerance and/or anti-social behaviour; .2
irregular/atypical mood changes (examples are irritability,
tiredness
and/or depression) .3 ignores normal checks and/or procedures;
and .4 increasing omissions, mistakes, and/or carelessness.
7 Long-term effects of sleep loss may lead to cardiovascular
diseases, gastrointestinal diseases, mental health problems and
stress. 8 The more signs and symptoms seafarers observe in others
and/or experience themselves, the more likely it is that alertness
is significantly reduced. Fatigue is not the only cause of such
symptoms, but when several occur together, it is likely to indicate
fatigue-related impairment. It is important that seafarers notify
crewmates and supervisors when they recognize that they or other
crew members are fatigued. It is important to have open
communication between seafarers, their crewmates and their
supervisors regarding fatigue prevention and detection. The
company's fatigue risk mitigation strategy should allow for open
communication and reporting between seafarers, their supervisors
and management levels regarding fatigue prevention and detection,
and should prohibit any action directed against a seafarer for such
communications or reports. What can seafarers do to help reduce and
manage the risk of fatigue on ships? 9 Obtain adequate sleep: The
most effective strategy to fight fatigue is to obtain adequate
quality, quantity and continuity of sleep. As indicated in module
2, the company should provide seafarers with an adequate sleep
opportunity for recovery. Insufficient sleep over several
consecutive days will impair alertness; only sleep can maintain or
restore performance levels. 10 Sleep is most valuable if obtained
in a single block. While a short sleep or nap can provide a
powerful boost in alertness, it does not eliminate the need for
longer periods of sleep. 11 There may be instances when seafarers
may not obtain adequate sleep, even though they are provided with
adequate sleep opportunity. The items mentioned below can all
affect the quantity and quality of sleep obtained:
.1 seafarers are working during the night and may simply be
unable to sleep during the day;
.2 seafarers' sleep may have been interrupted by colleagues,
unexpected
events or operational demands; .3 seafarers may suffer from a
sleep disorder, or other medical or physical
problem that keeps them awake;